Applied Immune Sciences has developed sterile polystyrene devices onto which monoclonal antibodies are covalently attached. These devices have been routinely used to separate cells from blood and bone marrow which have surface antigens speficic for the immobilized antibody. Moreover, these devices are effective in isolating hematopoietic stem cells from bone marrow and peripheral blood. The specific aim of this research proposal is to develop large scale cell separation devices based on our existing technology to efficiently purify peripheral blood stem cells in sufficient quantity for transplant. The procedure would provide a nontoxic, noninvasive procedure purged grafts. Autologous transplant with purified peripheral blood stem cells will offer several advantages to patients: 1) Collection of peripheral blood will take place in an apheresis center without general anesthesia; 2) In many cases the total number of stem cells collected and transplanted will be greater, 3) In many diseases the peripheral blood is less contaminated with tumor cells than is the bone marrow; 4) The purified stem cells will be purged of residual tumor cells; 50 Patients will be grafted with 100 fold smaller cell volumes, substantially reducing DMSO toxicities; 60 Animal experiments show that more rapid engraftment of myeloid cells may occur using purified stem cell grafts. Use of purified stem cells also dramatically reduces the storage space required in transplant units. Because of these advantages, commercialization of these devices should be possible.